Improvement in pulleys



J. AA. BURNAP.

PULLEY.

Patented Sept. 1, 1868.

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Letters Patent No. 81,860, dated September 1, I868.

IMPROVEMENT IN PULLEYS.

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TO ALL WHOM IT MAY CONCERN:

lie it known that I, JOHN A. BURNAP, of the city of Albany, county of Albany, and Stato of New York,

haveinventcd a. new and useful Improvement in Friction-Rollers for Pulleys, Wheels, fee., for the purpose of diminishing the friction of and facilitating-the revolutions of pulleys and other wheels; and I do hereby declare that the following is a. full, clear, `and. exact description of the construction and operation of the same, refer ence being had to the accompanying drawings, making :t par: of this specification, in which- Figure 1 is a view 'of the pulley .13, with itsrollers e c e c and c c e e', and ofthe bleek A, with n portion of it broken nrmy. I is the pin on which the pulley D revolves. F is u. llenge, in the eye of the pulley B, which separates the two series of rollers, c e c r: :tml c c c n', and serves :1s-u guard for euch serios of rollers, and also as o. side support for the pulley B. The rollers e f,- nnd c c e' are made of such a. size relatively1 to their length that they nre guided or kept in position by the contact oi' their end surfaces ugainstthe sides ofthe'chamhers in which they work without the nid of any frame, pivot, or other device.

Figure 2 is a. side und end view of the rollers in fig. l'.

Figure 3 represents an arrangement requiring only one series of rollers, extending through the eye ofthe ulle E iusteadof two series se :t1-ated b a. fleure, as dis ilu ed in fioul. Is this siecle-series arren ement` P P Q l a a g the diameter ofthe rollers is increased in proportion to 'their length, whereby they retain, with increased power, their distinctive feature of self-guidance. Y j

My improvement thus described is superior to anything in use, in that it is simple, consisting of but few parte, easily made, is strong enough for the heaviest ship or other tackle, diminishes friet-iemand facilitates the revolutions of :my wheel or pulley with which it may he used.

What I elf-lim as non', and desire to secure oy Letters Patent, isl.

1. The pulley and block, having the {rieti-on-rollers constructed :1nd :wronged so as to be self-guiding, in

the manner as described.

2. The combination ofthe pulley A, pulley-block 13, und two sots of cylindrlnl rollers, ce e lc and e' e' e' c', and flange F, all constructed and used as shown und dee-:ril'mllY 3. 'lhe arrangement, in the eye'of tnepulley B, ot two or more sets of cylindrical rollers, eonstruetcd'and kept in position by ineens shown and described.

v JOHN A. BURNAP.

Witnesses:

L. W. Srocxme JACOB Swrrzeu. 

